Gas-fired boiler



Aug. 5, 1930. G. H. IRWIN GAS FIRED oILER Filed oct. 17, 1927 2Sheets-Sheet l I l \l/// 7 3 w g M 6 0 J I@ w f 77 M :H HMMHHIAUWI NMI--l 1 .H w. 2 J A- H Q0 l-- m n 3 N WJ f v 5 g /f www N M G Q n 2 f L XFwd L #v fd x 3n L l L w Alll o\ 1 y n L u r|| L w 1 62/ M u L d u MW.Aa m Illv 7 oO 6 (f. J w

Aug. 5, 1930.4 G. H. IRWIN GAS FIRED BOILER Fi1 ed Oef. 17; 1927 2Sheets-Sheet 2 Patented Aug. 5, 1930 GFDRGE H. IRWIN, F CHICAGO, ELINOISy GAS-FIRES!) BOILER Application ned october 17, 1927'. serial m.226,568.

My invention relates to gas fired boilers artlcularly adaptable forsteam vor hot water eating systems or for heating water for industrialor household use.

An important object of the invention is to provide construction andarrangement for causing the water and the burning gas or heat to iiow incounter currents or streams, 'and to segregate the hot and cold zones ofwater and gases so that the heat convection'is uniform and perfect andto cause the expansion and contraction of the boiler sheets and tubes tobe uniform. A

Another important object is to provide an economizer boiler sectionconcentric with and surrounding the main .boiler section, into whicheconomizer section the cold water is fed and flows upwardly around firetubes through which the combustion gases iow downwardly to the smoke boxto exit through the stack, the water thus drawing the heat from suchgases for preliminary heating be.-

fore entering the main boiler section, the

economizer section also formin an insulatin jacket around the main bo'er section to re uce heat lossto a minimum.

Anotherimportant object is to provide baille means for causing thepreheated water from the economizer section to flow downwardly in thelower' part of the main boiler section and around the fire tubes to thebottom tube sheet before flowing upwardl to the steaming space at theupper part o the boiler.

Another important object is to burn the gas en masse in a lire boxclosed to the atmosphere and to produce a uniform and eliicient m'ixture of gas and airfor perfect flame and combustion conditionsirrespective of weath- 40 er or draft conditions; to thus eliminate the'evils of multiple separable, adjustable, as burner units andatmospheric burning. y means 'ofa blower I thoroughly mix gas and air inproper proportion and ositively feed the combustion mixture into t efire box below the fire tubes.

Another object is to dispense with pilot burners and to provide improvedand more reliable means or igniting the combustionsomixtureasitleavestlmhlowel-,suchmeans being preferably in the form ofa spark plug which may be readily controlled to function as soon as theblower is started and to insure ignition of the combustion mixture.

The above and other features of my invention are incorporated in thestructure shown on the drawings, in which Fig. 1 is a vertical diametralsection of the boiler structure. y

Fig. 2 is a section on plane 2-'2 Fig. 1, and 60 Fig. 3 is a section onplane 3-3 Fig. 1. The boiler structure comprises the outer cylindricalshell 1 from whose upper end exl tends the annular tube plate 2, and aninner cylindrical shell 3 concentric with but of less 65 diameter thanthe outer shell. Across the upper and lower ends of the shell 3 extendthe upper and lower tube 1sheets 4 and 5 respec tively in which areseated the fire tubes 6, these parts forming the main boiler section. Anangle bar ring 7 is secured around' the lower end of the shell 3 andrests on the cylindrical base 8 which has the bottom 9, the base sidesand bottom being lined with heat refractory material 10. The outer shell1 75 rests on the ring 7 and a band 11 assists in holding the -shellin'position.

Between the shells 1 and 3 and a distance above the bottom tube sheet 5is the annular tube sheet 12 which extends between the shell 80 Y 1 andthe lowe'r end of the intermediate shell 13 which is concentric with butspaced from shell 3 to leave the annular space or passage 14. Theannular top plate 2 extends between the upper end of the shell 13 andthe outer 95 shell 1. The shells 1 and 13 and the tube plates 2 and 12enclose the annular space 15 through which extend the lire tubes 16. Theshells 1 and 3 together with the tube sheet 12 and the ring 7 enclosethe annular smoke 90 space 17 which communicates with the lower ends ofthe tubes 16 and assage 14 and which at one side-is connecte with the'stack At one side of the boiler structure the water inlet pipe 19extends through the shell 1 to feed water into the space 15 at the lowerend thereof, and at the opposite side of theboilerstru'ctureapipeil()extendsthroughthefshellltooonnectwiththetopofthespx 1" 15, the pipe at its lower endextending through the shells 1 and 3 to connect w1th the water space ofthe main boiler section a distance above the bottom tube sheet 5 asindicated at 20.

Extendingdownwardlyfromtheuppertube sheet 4 to a. point below the pipeend 20 and above the bottom tube sheet 5 is the cylindrica] baffle shell21. This shell is concentric with but of less diameter than the shell 3to leave the intermediate boiler section 22 between these shells, andthrough this section extend the 'fire tubes 23 which seat at their endsin the upper and lower tube sheets 4 and 5.

Extending laterally from the upper end of the baille' shell 21 to theexterior of the lboiler is the steam header 24 which conducts the heatedsteam to vthe heating system .radiators. The baffle shell has also thepassage opening 25 at its upper end for the flow through the shell andto the steam header of steam generated in the space 22 by the lheat fromthe tubes 23. A water column structure 26' is connected by pipe 27 withthe in terior of the boiler to indicate the boiler water level.

On top of the boiler is the cap 28, preferably of sheet metal, whichforms the chamber 29 with which the various fire tubes communicate attheir upper ends. Preferably an inner wall 30 is provided to forminsulating space 31 which may be filled with heat insulating material.

Within the base 8 is the fire or combustion chamber 32 and through thebase wall is the opening 33 into which projects the outlet nozzle 34 ofa centrifugal blower 35 driven by an electric motor 36. Through piping37 gas and air are drawn into the blower in proper proportion andthoroughly mixed before delivery into the combustion chamber.

'To ignite the combustion mixture I preferably use electric sparks andone or. more spark plugs 38 are applied to the blower nozzle to projectsparks into the outflowing combustion mixture to ignite the same.Suitable and well' known electrical apparatus may be utilized to producethe sparking. As diagrammatically shown a cam or contact wheel 39cooperates with a contact 40 to make and break the electrical circuit 41fed by a current source 42. One terminal of the source connects with thecontact wheel and the other terminal with the blower frame, while thecontact 40 connects with one terminal of the spark plug whose otherterminal connects wlth the blower frame. The .contact wheel may beconnected to be rotated by the motor so that whenever the motor operatesthe blower to deliver combustion mixture the spark p lug will operate toignite the mixture. Operation of the motor may be controlled from adlstance by means of a switch 43 in the motor supply circuit.

Describing now the operation, the feed or Vreturn water enters at thebottom' of the space 15 through the pipe 19 and flows upwardly throughthe space to be preheated by the gases flowing downwardly through thetubes 16 and the annular passage 14 on their way toI the smoke chamber17. The preheated water flows downwardly through pipe 20 into the space22, and being cooler than the water at the bottom of themain boilersection, it iiows downwardly toward the hot tube sheet 5 to mix with thehot water and be further heated before flowing around the lower end ofthe baiile shell 21 and upwardly through the shell around the fire tubes6. The water also rises in the space 22 to be heated by the fire tubes23, the water level be ing at a. distance below the top tube sheet toleave space for the heated steam, the steam flowing out through theheader 24 for distribution. The steam generated in the space 22`findsits way through the passage 25 into the baiiie shell and from there tothe header 24.

` The space 15 forms the economizer section of the boiler as the wateris given a preliminary heating by the outlowing gases before it entersthe hot zone of the main boiler section. lln this economizer sectionVthe water flows counter to the gas flow through the tubes 16 andpassage 14 and extracts any available heat left in the gases before theyreach the stack. When the preheated water enters the main boiler sectionit again flows counter to the flame in the re tubes. This arrangementsegregates the hot and cold zones of water and gases so that theheatconveetion is uniform and perfect and the expanslon and contractionof the tubes andsheets are uniform. The economizer section acts also asan/insulating jacket to reduce heat loss to a minimum.

It will be noted that the combustion cham- A ber 32 is closed to theatmosphere, the combustion gas receiving itsproper air supply thoroughlyintermixed therewith in the l ing down and disturbing the molecularstructure of the gas with the admission of the correct quantity of air,and the delivery of the combustion mixture into the combustion chamberunder pressure sand speed. The feed is thus positive and independent ofany atmosphere or gas condition and is'not affected in any way by backdraft. l

The electrical ignition of the combustion by the spark' plug eliminatestroublesome pilot flames which may be readily extinguished by backdraft. With `my arrangement, the ignition operates only when the bloweris operating and combustion mixture is being delivered.;l

The boiler structure is of simple and comparatively inexpensiveconstruction. Practically all the parts can be cut from standard stockmaterial of any suitable metal. The structure is self contained and canbe completely assembled and tested in the shop prior to shipment.Installation cost is therefore materially reduced. Being practicallyentirely of sheet metal it is also comparatively light A and easilyshipped, handled and installed.

I do not desire to be limited to the exact structure and arrangementshown as changes and modifications are possible which would come withinthe scope of my invention.'

I claim 1. In a vertical lire tube boiler, the combination of a mainboiler section having updraft fire tubes, an economizer boiler sectionsurrounding the main boiler section and having down-draft ire tubes, anintermediate boiler section having up-draft re tubes, said economizersection-having a water inlet at its lower end and a water outlet at itsupper end whereby the water tlowstherein counter current to the draft,said outlet connecting with said intermediate section a distance abovethe lower end thereof, a connection between said intermediate and mainsections, means for causing the water to flow downwardly in saidintermediate and main sections counter current to the draft beforeflowing upwardly through said main section, and a steam delivery outletfrom the upper part of said main section.

2. In a vertical fire tube boiler, the combination of a main boilersection having up draft fire tubes, 4an economizer boiler sectionsurrounding the main boiler section and having down-draft lire tubes, anannular downdraft tire passage between said sections, a combustionchamber below said main boiler section, a cap above the main andeconomizer sections, a smoke box below the down-draft -ire tubes and astack'extending therefrom,

and means for causing the water to flow counter current tothe draft insaid economizer sectionand counter current to the draft at the lowerpart of themain boiler section.

v 3. In a vertical firel tube boiler, the combination of a main boilersection, having updraft fire tubes, an economizer boiler sectionsurrounding the' main boiler section and having down-draft re tubesconnected at their upper ends with the upper ends of the mainsectiontubes, a fire box below said vmain section tubes, a smokebox below saideconomizer section and a stack extending therefrom, said economizersection having a water inlet at its lower end and a water outletat itsupper end whereby water will flow in said sectlon counter current to thedraft, said outlet connecting with said main section a distance abovethe lower end thereof, a baie for caus- -ing the water from theeconomizer section to ow downwardly to the bottom of said main sectionbefore flowing upwardly in said main section, said boiler sections beingdisconnected from each other at their .upper ends, and a -tu es, anintermediate boiler section having 11p-draft `tubes and separated fromthe outer i section by a down-draft passage, a hood receiving the upperends of all said tubes, a furnace below the main and intermediatesections, a smoke box below the outer section and surrounding the mainand intermediate sections, a stack extending from said smoke box, saidouter section having a water inlet at its lower end and a water outletat 'its upper end, said outlet being connected with said intermediatesection a distance above the bottom thereof and said intermediatesection being connected with the main section at the bottom thereof, asteam delivery pipe extending from the upper part of said main section,and a. steam passage between the main and intermediate sections abovethe boiler water level.

5. In a vertical fire tube boiler, the combination of a main boiler4section, an economizer boiler section surrounding said main section, anintermediate boiler section between said main and economizer sections,said Y sections being connected in'series for the flow of water, a waterinlet for the economizer section, means causing the water to flowthrough the sections counter current to the direction of'the draftthrough the tubes in the sections, a delivery pipe for steam extendingfrom the main section, and a passage from the steam space of theintermediate4 section tothe steam space of the main section for the flowof steam from the intermediate section into and through the main sectionbefore reaching the delivery pipe.

' 6. In a vertical fire tube boiler, the combination of a main boilersection having up draft fire tubes, an economizer boiler sectionsurrounding said main section and having down draft tire tubes, and anannular down draft fire passage between said sections, said economizersection having a water inlet at its lower end and a water outlet at itsupper end connected with the main boiler section below the water leveltherein. l

l 7. In a' vertical fire tube boiler, the combination of a main boilersection having up draft tubes, an economizer boiler section having downdraft tubes, an intermediate boiler nu A let from the top of said mainsection, and a steam passage between said main and intermediate sectionsabove the water level there- 8. In a vertical lire tube boiler, thecombination of a main boiler section comprising upper and lower tubesheets and lire tubes extending between said sheets, a baille shel'l eX-tending downwardly lfrom said top sheet to within a short distance ofthe lower sheet to divide said main boiler section into inner and outerboiler parts, an economizer boiler section surrounding the main boilersection and separated therefrom by an annular lire passage, I'ire tubesin said economizer section, a furnace below the main boiler section, asmoke cap above said main boiler section and said ec'onomizer sectionreceiving the gases from said main boiler section tubes, a smoke boxsurrounding said main boiler section below said economizer section toreceive the gas from said economizer section tubes and from said iirepassage, a stack leading from said smoke boX, a water inlet at the lowerend of said economizer section and an outlet therefrom connected withsaid inner boiler part a distance above the lower end of said bailleshell, a steam supply outlet from the top of said inner boiler part, anda connection for the flow of steam from said outer boiler` part tothe'steam space of said inner boiler part.

9. In a vertical lire tube boiler, the' combination of a shell havingupper and lower tube sheets connected by lire tubes, a baille shellextending downwardly from said upper sheet to within a short distance ofsaid lower sheet to form inner and outer boiler sections, a water inletto said outer section a distance above the lower end of said balileshell but below the boiler water level whereby water must flowdownwardly before iowing upwardly in the inner boiler section, an outletforsteam from one side of said inner boiler section, and a steam passagebetween the opposite side of said inner boiler section andv said outerboiler section whereby the steam .from said outer section must flowacross the nner section before reaching said steam out- 1Q. In avertical fire tube boiler, the combination of a main boiler sectionhaving updraft re tubes, an economizer boiler section surrounding themain boiler sectionand having downclraft re tubes, an annular downdraftfire passage between said sections, a combustion chamber below said mainboiler section, a cap above the main and economizer sections, a smoke.box below the downdraft fire tubes and fire assage and a stack extendingfrom said smo e box.

11. In a vertical re tube boiler, the combinat-ion of a main boilersection having ire tubes, an economizer boilersection surrounding saldmain boiler section and having fire tubes, a contlnuous annular repassage sepa.-

GEORGE I-I. IRWIN.

